Independently and not as an agent of the Government, the contractor shall furnish all the necessary services, qualified personnel, material, equipment, and facilities not otherwise provided by the Government as needed to maintain and update the data and name and address files of the Child Health and Development Studies (CHDS). On September 30, 2006, the NICHD awarded a contract to the Public Health Institute, now ongoing, to update and maintain the Child Health and Development Studies name and address data files of 50,093 individuals involved in the CHDS. This contract will end on September 29, 2011. The proposed contract will continue this effort from September 30, 2011 through September 29, 2013. The new contract has three primary aims: (1) to maintain and update the name and address files of the Child Health and Development Studies; (2) to facilitate future biomedical and psychosocial studies of this national public health resource which includes a large serum collection; and (3) to provide an honest broker mechanism to maintain patient confidentiality, by acting as a neutral intermediary between outside investigators and the subjects of the CHDS and their serum samples.